Side reinforcing member of a shoe

ABSTRACT

A running shoe includes a sole, an upper connected to the sole, a foot cavity defined at least in part by an inside surface of the upper. The sole includes an outsole, a midsole disposed over the outsole, and one or more side reinforcing members incorporated into the midsole, the side reinforcing member including a first portion extending into an interior of the midsole from an outer face of the midsole and a second portion extending along the outer face of the midsole.

BACKGROUND

Athletic shoes may be used in variety of circumstances and for a variety of purposes. Depending on the intended use of a shoe, it may be constructed differently or include different components than other types of shoes.

Running shoes can be constructed for multiple types of running environments and types of running. Often, road running shoes are constructed for running on pavement and other surfaces that are generally flat. These types of running shoes tend to be lightweight and flexible. Additionally, they include material to cushion or stabilize feet during repetitive strides on hard, uneven surfaces.

Cross-training shoes are constructed for workouts that include both aerobic and anaerobic types of activities. The soles of these shoes often have more surface area in contact with the ground to provide stability.

Trail-running shoes are often constructed for off-road routes that are rugged and include other obstacles such as puddles, mud, rocks, roots, and so forth. These shoes include aggressive treads for improved traction and are fortified to add stability and support. Generally, the outsole of the shoe extends substantially beyond the edges of the shoe's upper to provide the additional stability.

The sole of these types of shoes typically includes a midsole, which is formed of a relatively soft layer of material compared to the outsole material. Some of the primary functions of the midsole is to provide cushioning to the user and reduce the amount of impact force experienced by the body while running. It is well understood in the industry, however, that there is a tradeoff between the amount of cushioning provided by the midsole and the stability of the shoe. The stability refers the amount which the shoe is able to resist pronation or tilting of the foot. A midsole that allows for too much pronation can lead to an inefficient foot strike and/or injury in a user. Accordingly, there is a desire for a midsole that provides a high amount of cushioning, while also providing a high amount of stability.

One example of a running shoe including cushioning and stability enhancing elements is disclosed in U.S. Pat. No. 5,625,964 to Lyden et al. Lyden discloses a shoe that attempts to achieve a high amount of both cushioning and stability by having a midsole that includes multiple gas chambers with varying pressures that are divided to provide a desired point of flexion. However, the pressures in the cushioning gas chambers may change over time due to leakage which may attenuate the desired cushioning and stability characteristics. Further, the point of flexion may not be advantageously placed for all users because physiology and running motion are highly variable between users. This reference is herein incorporated by reference for all that it contains.

SUMMARY

In one embodiment, a running shoe includes a sole, including an outsole, a midsole disposed over the outsole, the midsole including, an interior, an outer face, a side reinforcing member incorporated into the midsole, the side reinforcing member including a first portion extending into the interior of the midsole from the outer face of the midsole, and a second portion extending along the outer face of the midsole. The shoe can further include an upper connected to the sole, and a foot cavity defined at least in part by an inside surface of the upper.

A face of the second portion of the side reinforcing member can be disposed directly on the outsole.

The first portion of the side reinforcing member can extend between about 10 millimeters to about 20 millimeters into the interior of the midsole from the outer face of the midsole.

The first portion of the side reinforcing member can have an approximately “L” shaped cross-section.

The second portion of the side reinforcing member can extend between about 5 millimeters to about 15 millimeters along the outer face of the midsole.

The side reinforcing member can be incorporated into the midsole at a position between a midpoint of the sole and a front edge of the sole.

The sole can have a toe portion, and the side reinforcing member can be incorporated into the midsole at a position between a midpoint of the sole and the toe portion of the sole.

The sole can have a heel portion, and the side reinforcing member can be incorporated into the midsole at the heel portion.

The first portion and the second portion of the side reinforcing member can each have a thickness of between about 1 millimeter to about 1.5 millimeters.

The side reinforcing member can have a characteristic of having a Shore A hardness rating of about 80 to about 100.

The side reinforcing member can have a stiffness greater than a stiffness of the midsole.

The side reinforcing member can include thermoplastic polyurethane (TPU).

In one embodiment, a running shoe can include a sole including an outsole, a midsole disposed over the outsole, the midsole including, an interior, and an outer face, a first side reinforcing member incorporated into the midsole, including a first portion extending into the interior of the midsole from the lateral outer face of the midsole, a second portion extending along the lateral outer face of the midsole, a second side reinforcing member incorporated into the midsole, including a first portion extending into the interior of the midsole from the medial outer face of the midsole, a second portion extending along the medial outer face of the midsole, a third side reinforcing member incorporated into the midsole, including a first portion extending into the interior of the midsole from the lateral outer face of the midsole, a second portion extending along the lateral outer face of the midsole. The shoe can further include an upper connected to the sole, and a foot cavity defined at least in part by an inside surface of the upper.

The first side reinforcing member can be positioned between a midpoint of the sole and a toe portion of the sole.

The second side reinforcing member can be positioned between a midpoint of the sole and a toe portion of the sole.

The third side reinforcing member can be positioned at a heel portion of the sole.

The midsole can include a lateral outer face portion and a medial outer face portion, wherein the first and third side reinforcing members extend along the lateral outer face portion, and wherein the second side reinforcing member extends along the medial outer face portion.

Each of the first, second, and third side reinforcing members can have a characteristic of having a Shore A hardness rating of about 80 to about 100.

Each of the first, second, and third side reinforcing members can have a stiffness greater than a stiffness of the midsole.

In one embodiment, a running shoe can include a sole having a midpoint, a toe portion, and a heel portion, the sole including an outsole, a midsole disposed over the outsole, including an interior, a lateral outer face, a medial outer face, a first side reinforcing member incorporated into the midsole and positioned between the midpoint of the sole and the front toe portion of the sole, including a first portion disposed directly on the outsole and extending into the interior of the midsole from the lateral outer face of the midsole, a second portion extending along the lateral outer face of the midsole, a second side reinforcing member incorporated into the midsole and positioned between the midpoint of the sole and the toe portion of the sole, including, a first portion disposed directly on the outsole and extending into the interior of the midsole from the medial outer face of the midsole, a second portion extending along the medial outer face of the midsole, a third side reinforcing member incorporated into the midsole and positioned at the heel portion, including a first portion disposed directly on the outsole and extending into the interior of the midsole from the lateral outer face of the midsole, a second portion extending along the lateral outer face of the midsole, wherein each of the first, second, and third side reinforcing members exhibits a characteristic of having a stiffness greater than a stiffness of the midsole, an upper connected to the sole; and a foot cavity defined at least in part by an inside surface of the upper.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate various embodiments of the present apparatus and are a part of the specification. The illustrated embodiments are merely examples of the present apparatus and do not limit the scope thereof.

FIG. 1 illustrates a lateral side view of an example of a running in accordance with the present disclosure.

FIG. 2 illustrates an exploded view of an example of a running shoe in accordance with the present disclosure.

FIG. 3 illustrates a bottom view of an example of a running shoe in accordance with the present disclosure.

FIG. 4A illustrates a view of an example of a side reinforcing member of a shoe in accordance with the present disclosure.

FIG. 4B illustrates a view of an example of a side reinforcing member of a shoe in accordance with the present disclosure.

FIG. 4C illustrates a view of an example of a side reinforcing member of a shoe in accordance with the present disclosure.

FIG. 4D illustrates a view of an example of a side reinforcing member of a shoe in accordance with the present disclosure.

Throughout the drawings, identical reference numbers designate similar, but not necessarily identical, elements.

DETAILED DESCRIPTION

FIG. 1 depicts an example of a running shoe 100. In this example, the running shoe 100 includes a sole 102 and an upper 104 connected to the sole 102. The sole 102 and the upper 104 collectively form a foot cavity 106 that receives a foot of the user.

The foot cavity 106 can include a sock liner that lines the bottom of the foot cavity 106. Also, the side walls of the foot cavity 106 can include other types of cushioning that reduce the jarring impacts when the user's shoe strikes the running surface and holds the upper snuggly against the user's feet throughout the running motion. In some cases, the cushioning lines the entire surface of the foot cavity's wall. In other examples, the cushioning lines just a subset of the foot cavity 106.

In this example, the running shoe's upper 104 includes a low top profile where the upper terminates underneath or at the user's ankle. The low top profile provides the running shoe with a lower weight and provides the user additional movement.

The sole 102 includes an outsole 110, a midsole 112, and one or more side reinforcing members (114; 116; 118, FIG. 3) as described herein.

Referring to FIG. 2, an exploded view of the sole 102 of the shoe 100 depicted in FIG. 1 is illustrated according to one example. The sole 102 includes an outsole 110 having a desired tread or pattern on its lowermost surface for engagement with a running surface. In the embodiment shown, the tread includes a variety of lugs or other protrusions in that might be considered an aggressive pattern used for trail-running. The outsole can additionally include a toe bumper or toe guard providing some protection for the users toes as well as providing an ergonomic traction surface associated with a runner rolling up onto and pushing off of their toes while they run.

The sole 102 additionally includes a midsole 112 positioned about the outsole 110. The midsole 112 is configured to provide cushioning and shock absorption to the runner. In one embodiment, the midsole can be configured of ethyl vinyl acetate (EVA). Incorporated into the midsole are one or more side reinforcing members. In this example, the sole 102 includes three side reinforcing members 114, 116, 118 incorporated into the midsole 112. A side reinforcing member includes a first portion that extends from an outer face of the midsole 112 in the direction of, or into, the interior of the midsole 112. A side reinforcing member also includes a second portion that extends along an outer face of the midsole 112. Each side reinforcing member 114, 116, 118 can be formed of a polymer or other material having a Shore A hardness of between about 80 and about 100. In this example, the side reinforcing members 114, 116, 118 can be formed from thermoplastic polyurethane (TPU). The side reinforcing members 114, 116, 118 can be molded or formed separately from the midsole 112 and fitted therein, or in some embodiments, and as in this example, the side reinforcing members 114, 116, 118 can be co-molded with the midsole 112. The side reinforcing members 114, 116, 118 have a characteristic of having a stiffness greater than a stiffness of the midsole 112.

The sole 102 further includes an insole above the midsole 112. The insole provides a foundation on which a user's foot presses when wearing the shoe 100. The sock liner of the shoe can rest on the insole. The insole can provide some cushioning, but also provides structure and torsional stability to the shoe.

FIG. 3 depicts a bottom view of an example of a running shoe 100. In this example, the running shoe 100 has a sole 102 with a an outsole 110. The sole 102 includes a forefoot, or toe portion 122, that underlies the toes of a user's foot when the shoe is properly fitted to the user. In some cases, the toe portion 122 can extend from an edge of the midsole 112 to a position about ⅓rd to about ⅕th along the length of the midsole 112. The sole 102 also includes a heel portion 124 that underlies the heel of a user's foot when the shoe is properly fitted to the user. In some cases, the heel portion 124 can extend from an edge of the midsole 112 to a position about ⅓rd to about ⅕th along the length of the midsole 112.

A first side reinforcing member 114 is positioned at a lateral edge of the midsole 112 at the heel portion 124 of the midsole 112. As can be seen in FIG. 3, the first portion of the side reinforcing member 114 has an approximately rectangular shape. A second side reinforcing member 116 is located at the lateral edge of the midsole and is positioned between a midpoint or midline of the sole 112 and the toe portion 122. A third side reinforcing member 118 is located at a medial edge of the midsole and is positioned between a midpoint or midline of the sole 112 and the toe portion 122. As can be seen in FIG. 3, the first portion of each of the side reinforcing members 114, 116, 118 has an approximately rectangular shape. However, other shapes of the first portion are expressly contemplated, for example, circular, square, or ovoid, and each first portion need not have the same shape as any of the other first portion of the side reinforcing members 114, 116, 118.

FIG. 4A depicts a cross-sectional view of an example of a side reinforcing member 114 of a running shoe 100. As described herein, the side reinforcing member 114 includes a first portion 142 and a second portion 144. The first portion 142 can have a width of between about 10 millimeters to about 20 millimeters, and thus can extend between about 10 millimeters to about 20 millimeters into the interior of the midsole 112 as depicted, for example, in FIG. 3. The first portion 142 can have a thickness of between 1 millimeter to about 1.5 millimeters and can have a length of between about 30 millimeters to about 60 millimeters. As shown, for example, in FIG. 3, the first portion 142 have can an approximately rectangular shape, although other shapes, including, but in no way limited to circular, triangular, quadrilateral, and the like are expressly contemplated.

The second portion 144 of the side reinforcing member is positioned approximately perpendicular to the first portion 142, such that an edge of the second portion 144 aligns with an edge of the first portion 142. The second portion 144 can have a height of between about 5 millimeters to about 15 millimeters, and thus can extend between about 5 millimeters to about 15 millimeters along an outer face of the midsole 112. as depicted, for example, in FIGS. 1-2. The second portion 144 have a thickness of between 1 millimeter to about 1.5 millimeters and can have a length of between about 30 millimeters to about 60 millimeters. The length of the second portion 144 can be substantially the same as the length of the first portion 142. As shown, for example, in FIGS. 1-2, the second portion 144 have can an approximately triangular shape, such as an obtuse scalene triangular shape, although other shapes are expressly contemplated as will be understood by the skilled artisan.

FIG. 4B depicts a cross-sectional view of an example of a side reinforcing member 214 of a running shoe. As described herein, the side reinforcing member 214 includes a first portion 242 and a second portion 244. In this example, the side reinforcing member 214 can have a composite or layered construction, including layers 252, 254, and 256 which can be laminated or otherwise adhered or fused together to form the side reinforcing member 214. In this example, the layer 254 can have a stiffness and/or hardness, less than that adjacent layer 252, while layer 256 can have a stiffness and/or hardness less than that of layer 254. In this example, the stiffness of the layers can decrease from an exterior of the side reinforcing member towards the midsole. Thus, layer 256 can have a stiffness and/or hardness closer to the stiffness and/or hardness of the midsole material than the outer layer 252. In this way, a layered or composite side reinforcing member 214 can reduce or prevent fatigue of the midsole material where it is adjacent to the side reinforcing member 214.

FIG. 4C depicts a cross-sectional view of an alternative example of a side reinforcing member 314 of a running shoe. As described herein, the side reinforcing member 314 includes a first portion 342 and a second portion 344.

FIG. 4D depicts a cross-sectional view of an alternative example of a side reinforcing member 414 of a running shoe. As described herein, the side reinforcing member 414 includes a first portion 442 and a second portion 444.

GENERAL DESCRIPTION

In general, the system and method disclosed herein can provide users with a running shoe that has one or more side reinforcing members to provide additional stability to the running shoe when in use. The one or more side reinforcing members can be incorporated into the midsole of the running shoe. The side reinforcing members allow for a midsole having a desired amount of cushioning, without the reduced stability which such cushioning might typically result in, absent the side reinforcing members. The side reinforcing members can be formed of a stiffer material than the midsole, and in this way can prevent or inhibit pronation of the foot of a user without detracting from the cushioning provided by the midsole.

The running shoe of the present system and method can include a sole that is made up of two distinct layers, the outsole and the midsole. The outsole can contact the ground. The outsole can be made of a hard, abrasion resistant material that resists wear, provides traction, and allows flexibility

The outsole can include a rubber compound with a high carbon content at the heel and in the toe box areas. The outsoles can be constructed with studs or ridges to provide traction on slippery surfaces, such as wet grass or slick pavement. In some examples, the outsole can include transverse grooves in the toe box area so that the running shoe is more flexible in the toe box area when the user's weight is loaded against the ball of the user's foot while the heel is raised off of the ground. Generally, the wider the outsole, the greater stability the outsole provides the foot. However, the wide outsole also increases the weight of the shoe. In some examples, the running shoe can include an outsole that is just as wider or has a width that is less than 5.0 percent greater than width of the corresponding sections of the shoe. Having a narrow outsole reduces the weight of the running shoe.

The midsole of the sole is located above the outsole. The midsole is made of a material that provides cushioning. The total height of the midsole and outsole under the heel can be about 1.0 inch and the total height of the midsole and outsole under the toe box is about 0.6 inches. The difference in sole thickness between the heel and toe box can reduce the strain on the user's Achilles tendon. This drop in the height of the sole from the heel to the toe box can affect how the user's foot strikes the ground. In some cases, the heel drop can range from 4 mm to 10 mm. The running shoe's sole can be thicker than the soles of shoes that are intended for walking or other types of activities.

The midsole can be constructed of various materials to provide cushioning. In some cases, the midsole is made of ethyl vinyl acetate (EVA) or polyurethane. EVA is a copolymer of ethylene and vinyl acetate that has microscopic air bubbles within it that makes it lightweight, while providing a good amount of cushioning. Polyurethane also has a microscopic air bubble structure like EVA but is generally firmer and more resistant to compression than EVA.

Conventional uppers are made of a combination of lightweight nylon to reduce the running shoe's weight. The upper of a running shoe can also incorporates a stiff heel counter that is commonly stiffer than in other athletic shoes to help control excessive pronation or supination during running.

Any appropriate type of running shoe can be used in accordance with the principles described herein. For example, the running shoe can include a low-top profile where the upper terminates just below the user's ankle. While a low-top upper can provide less lateral stability, the running shoe is lighter. In other examples, the running shoe includes a high-top profile. In this example, the running shoe includes an upper that extends over the user's ankle.

In some embodiments, a side reinforcing member can be incorporated into the midsole and positioned at a lateral or medial outer edge of the midsole. The side reinforcing member can be positioned at a heel portion of the midsole, and/or between the toe portion of the midsole and a midpoint thereof. In some example, a side reinforcing member can be positioned so as to provide a maximum stabilizing effect. In some embodiments, a shoe can include three side reinforcing members, a first side reinforcing member positioned at a heel portion of the sole and at a lateral edge of the midsole, a second side reinforcing member positioned between the toe portion of the sole and a midpoint of the sole at the lateral edge of the midsole, and a third side reinforcing member positioned between the toe portion of the sole and a midpoint of the sole at the medial edge of the midsole.

In some embodiments, a side reinforcing member can include a first portion and a second portion disposed approximately perpendicular to the first portion. Accordingly, the side reinforcing member can have an approximately “L” shaped cross-section. The first portion can be approximately rectangular, for example it can be rectangular with rounded corners or edges, although other shapes are expressly contemplated. The first portion can have a width of between about 10 millimeters to about 20 millimeters. Therefore, in some embodiments, the first portion can extend between about 10 millimeters to about 20 millimeters into the interior of the midsole when incorporated therein. The first portion can have a thickness of between 1 millimeter to about 1.5 millimeters and can have a length of between about 30 millimeters to about 60 millimeters.

The second portion can be approximately triangular, for example it can be triangular with rounded corners or edges, although other shapes are expressly contemplated. The second can have a height of between about 5 millimeters to about 15 millimeters, and thus can extend between about 5 millimeters to about 15 millimeters along an outer face of the midsole when incorporated therein. The second portion can have a thickness of between 1 millimeter to about 1.5 millimeters and can have a length of between about 30 millimeters to about 60 millimeters. In some embodiments, the first and second portions can have substantially identical lengths.

In some embodiments, when incorporated into the midsole, the first portion can extend its full width into the interior of the midsole. In some embodiments, the midsole can have a cut-out or recess corresponding to the shape of the side reinforcing member. In some embodiments, when incorporated into the midsole, the second portion can extend along the outer face of the midsole. In some examples, the side reinforcing member can be incorporated into the midsole such that a surface of the side reinforcing member, for example a surface of the first portion can be directly disposed on and in contact with the outsole.

In some embodiments, the side reinforcing member can be formed of a polymer or other material having the properties described herein. In some embodiments, the side reinforcing member is formed of a material having a Shore A hardness rating of between about 80 and about 100. In some examples, the side reinforcing member can be formed of thermoplastic polyurethane (TPU). Importantly, in some embodiments, the side reinforcing member can be formed of a material having a greater stiffness than the material forming the midsole. In this way, the midsole can provide for a desired amount of cushioning, while the comparatively stiffer side reinforcing member can prevent or inhibit pronation of the shoe and foot without substantially impacting the cushioning of the midsole material.

In some embodiments, the stiffness and/or hardness of the side reinforcing member can vary from an outer surface towards the inner surface that contacts the midsole of the shoe. The stiffness and/or hardness can vary from a first stiffness and/or hardness to a second, lower stiffness and/or hardness. This second, lower stiffness and/or hardness can be closer to the stiffness and/or hardness of the material forming the midsole than the first stiffness and/or hardness. By reducing the stiffness and/or hardness towards the midsole, the disparity between the stiffness and/or hardness of the midsole and the portion of the side reinforcing member that contacts the midsole can be reduced so as to reduce, inhibit, or prevent the degradation of the midsole due to fatigue. In some examples, the stiffness and/or hardness can vary continuously along a cross-section of the side reinforcing member, however in some other examples the stiffness and/or hardness can vary in a step-wise fashion. In some embodiments, the side reinforcing member can have a layered construction, where each layer has a different stiffness and/or hardness to achieve the variance in stiffness and/or hardness. In some embodiments, the stiffness and/or hardness can be varied by varying an amount of an additive or component in the material forming the side reinforcing member.

In some embodiments, a side reinforcing member can be co-molded with the midsole. However, in some other embodiments, the side reinforcing member can be molded separately and incorporated into the midsole at a later point. In some embodiments, the side reinforcing member can be permanently fixed to the midsole, for example as a result of the molding process or by an adhesive. However, in some other embodiments, the side reinforcing member can be removable from the midsole. For example, in some cases, the side reinforcing member can be replaceable by a user in the midsole. 

What is claimed is:
 1. A shoe, comprising: a sole, including; an outsole; a midsole disposed over the outsole, the midsole including an interior and an outer face; a side reinforcing member incorporated into the midsole, the side reinforcing member including a first portion extending into the interior of the midsole from the outer face of the midsole, and a second portion extending along the outer face of the midsole; an upper connected to the sole; and a foot cavity defined at least in part by an inside surface of the upper.
 2. The shoe of claim 1, wherein a face of the second portion of the side reinforcing member is disposed directly on the outsole.
 3. The shoe of claim 1, wherein the first portion of the side reinforcing member extends between about 10 millimeters to about 20 millimeters into the interior of the midsole from the outer face of the midsole.
 4. The shoe of claim 1, wherein the side reinforcing member has an approximately “L” shaped cross-section.
 5. The shoe of claim 1, wherein the second portion of the side reinforcing member extends between about 5 millimeters to about 15 millimeters along the outer face of the midsole.
 6. The shoe of claim 1, wherein the side reinforcing member is incorporated into the midsole at a position between a midpoint of the sole and a front edge of the sole.
 7. The shoe of claim 1, wherein the sole has a toe portion; and wherein the side reinforcing member is incorporated into the midsole at a position between a midpoint of the sole and the toe portion of the sole.
 8. The shoe of claim 1, wherein the sole has a heel portion; and wherein the side reinforcing member is incorporated into the midsole at the heel portion.
 9. The shoe of claim 1, wherein the first portion and the second portion of the side reinforcing member each have a thickness of between about 1 millimeter to about 1.5 millimeters.
 10. The shoe of claim 1, wherein the side reinforcing member has a characteristic of having a Shore A hardness rating of about 80 to about
 100. 11. The shoe of claim 1, wherein the side reinforcing member has a stiffness greater than a stiffness of the midsole.
 12. The shoe of claim 1, wherein the side reinforcing member includes thermoplastic polyurethane (TPU).
 13. A running shoe, comprising: a sole, including; an outsole; a midsole disposed over the outsole, the midsole including an interior, and an outer face; a first side reinforcing member incorporated into the midsole, the first side reinforcing member including a first portion extending into the interior of the midsole from the outer face of the midsole and a second portion extending along the outer face of the midsole; a second side reinforcing member incorporated into the midsole, the second side reinforcing member including a first portion extending into the interior of the midsole from the outer face of the midsole, and a second portion extending along the outer face of the midsole; a third side reinforcing member incorporated into the midsole, the third side reinforcing member including a first portion extending into the interior of the midsole from the outer face of the midsole and a second portion extending along the outer face of the midsole; an upper connected to the sole; and a foot cavity defined at least in part by an inside surface of the upper.
 14. The running shoe of claim 13, wherein the first side reinforcing member is positioned between a midpoint of the sole and a toe portion of the sole.
 15. The running shoe of claim 13, wherein the second side reinforcing member is positioned between a midpoint of the sole and a toe portion of the sole.
 16. The running shoe of claim 13, wherein the third side reinforcing member is positioned at a heel portion of the sole.
 17. The running shoe of claim 13, wherein the midsole includes a lateral outer face portion and a medial outer face portion; wherein the first and third side reinforcing members extend along the lateral outer face portion; and wherein the second side reinforcing member extends along the medial outer face portion.
 18. The running shoe of claim 13, wherein each of the first, second, and third side reinforcing members has a characteristic of having a Shore A hardness rating of about 80 to about
 100. 19. The running shoe of claim 13, wherein each of the first, second, and third side reinforcing members has a stiffness greater than a stiffness of the midsole.
 20. A running shoe, comprising: a sole having a midpoint, a toe portion, and a heel portion, the sole including; an outsole; a midsole disposed over the outsole, the midsole including an interior, a lateral outer face, and a medial outer face; a first side reinforcing member incorporated into the midsole and positioned between the midpoint of the sole and the front toe portion of the sole, including: a first portion disposed directly on the outsole and extending into the interior of the midsole from the lateral outer face of the midsole; and a second portion extending along the lateral outer face of the midsole; a second side reinforcing member incorporated into the midsole and positioned between the midpoint of the sole and the toe portion of the sole, including: a first portion disposed directly on the outsole and extending into the interior of the midsole from the medial outer face of the midsole; and a second portion extending along the medial outer face of the midsole; a third side reinforcing member incorporated into the midsole and positioned at the heel portion, including: a first portion disposed directly on the outsole and extending into the interior of the midsole from the lateral outer face of the midsole; and a second portion extending along the lateral outer face of the midsole; wherein each of the first, second, and third side reinforcing members exhibits a characteristic of having a stiffness greater than a stiffness of the midsole; an upper connected to the sole; and a foot cavity defined at least in part by an inside surface of the upper. 